1. Field of the Invention
The invention relates to an apparatus for the recovery of an inert gas, particularly, for recovering CO2 gas, for use in counterpressure filling machines, the filling elements of whichxe2x80x94prior to introduction of a liquid filling material into a containerxe2x80x94evacuate this container and at least prepressurize this container with an inert gas under pressure from the pressurizing gas distribution channel, and which elements, during the subsequent introduction of a filling material, conduct the inert gas containing return gas displaced from a corresponding container into a return gas collection channel.
2. Background Information
Such a method and a corresponding apparatus for filling a liquid, especially carbon dioxide-containing filling material under counterpressure into bottles or the like containers, are known (EP A03 31 137). In this, it has also been proposed, in order to reduce the consumption of inert gas, or, respectively, CO2 gas, in the pressurizing phase, to utilize, for rinsing/washing, or purging, or flushing, as well as for partial prepressurizing of the corresponding container, return gas from a return gas channel of the filling machine, by which channel is removed return gas that has been displaced during filling of the containers. The return gas channel contains the return gas under a predetermined pressure and is in communication with a conduit by way of which excess of return gas is passed, for example, to the atmosphere or to the equipment for the preparation of inert gas. By way of utilization of the return gas from the return gas channel for rinsing/washing and partial prepressurizing of the containers there results a reduction in consumption of an inert gas. However, it is of detriment that all of the inert gas, displaced during filling from the corresponding container, is reaching the return gas channelxe2x80x94the pressure of which is markedly below the filling pressure, that is, below that pressure which is present in the interior space of the corresponding container at the conclusion of prepressurizing. The inert gas that is displaced during filling can, accordingly, be reused only for the rinsing/washing and the partial prepressurizing.
It is further known to utilize in counterpressure filling machines that return gas which is in the form of a CO2-air-mixture and which is obtained during the filling of containers or, respectively, bottlesxe2x80x94which hereinafter is referred to as xe2x80x9cinert gasxe2x80x9d, and in this especially as CO2 gas, and which comprises a large quantity of CO2, with an order of magnitude of 80 to 90 percent, after a conditioning or, respectively, recovering of the pressurizing gas for the prepressurizingxe2x80x94but also to the preceding rinsing/washing of the containers to be filled in order to reduce the CO2 consumption and to protect the environment due to the reduced release of CO2 gas. The recovery is carried out in this essentially thereby that in a mixing apparatus pure CO2 is added to the CO2 gas that is present as return gas.
It is the aim of the invention to provide an apparatus for such a recover, which apparatus ensures the provision of an inert gas with greatly improved quality and to improve a method, or, respectively, an apparatus of the type referred to in the foregoing, in such a way that there results a substantial reduction of also the required amount of inert gas which is maintained at the filling pressure.
The invention teaches that this object can be accomplished by an apparatus for the recovery of an inert gas characterized thereby that a first evacuation system is provided with which the air can be removed from the bottle, and then there is carried out a prepressurizing of the bottles using an inert gas; and a second evacuation system is provided with which can be removed and collected, independently of the first evacuation, the inert gas that is being removed by suction.